The goal of this proposal is to acquire funds to purchase a Scanco VivaCT 75 high speed in vivo micro- computed tomography (<CT) instrument for 3-dimensional imaging and quantitative analyses of trabecular and cortical bone properties in longitudinal studies using small animal (mouse and rat) models. There is no similar instrument available on the University of Massachusetts Medical School (UMMS) campus or in any of the colleges and universities in the Worcester, central Massachusetts area. This in vivo <CT scanner is to be shared among 8 users for the assessment of skeletal abnormalities in genetic mouse or rat models, design and characterization of new biomaterial implants for expedited bone repair, and addressing novel therapeutic approaches for osteoarthritis, rheumatoid arthritis, and metastatic bone diseases. These on-going studies can significantly benefit from the instrument's capability to carry out longitudinal characterization of bone tissue and quantitation of multiple parameters that reflect bone formation and resorption in live small animals. The long- term growth of translational research at UMMS in the areas of cancer, aging, diabetes, and orthopedic care where the testing of the skeletal complications associated with these diseases in small animal models can be stimulated with the non-invasive in vivo <CT imaging capability. PUBLIC HEALTH RELEVANCE: The requested Scanco VivaCT 75 high-speed in vivo micro-computed tomography ([unreadable]CT) instrument will provide the means to generate quantitative data that is necessary for evaluating bone phenotypes, bone pathologies and novel therapeutic strategies to inhibit bone resorption and stimulate bone formation. This instrument will contribute to the treatment of skeletal disorders in a number of major areas of health concern: 1) hard-to-heal skeletal defects due to trauma, aging, metabolic diseases and tumor resection;2) the debilitating metastatic diseases of bone;and 3) bone loss in osteoarthritis and rheumatoid arthritis that affects millions of people worldwide.